Three dimensional (3D) information about objects such as silicon wafers, printed circuit boards, reticles, flat panel display or other substrate shaped objects can be obtained in various manners that offer different tradeoffs between speed and accuracy.
Height 3D metrology requires balancing between speed and resolution/accuracy. When SEMI production worthy (full wafer metrology), fast method is required, triangulation is often the tool of choice.
Most of the industries known height triangulation systems include a dedicated 3D camera that is responsible to convert a triangulation image into 3D data.
Examples of such dedicated cameras could be found “off the shelf” from SICK-IVP (“Ranger” series), Automation Technology (“C” series), Photon Focus (“MV” series) etc. All of the mentioned examples implement either very primitive and lower accuracy 3D algorithm or a very accurate but unacceptably slow algorithm. For example, the existing dedicated 3D cameras can perform trivial, low accuracy 3D reconstruction algorithm as fast as 24K fps. On contrary, implementing high resolution accurate 3D reconstruction takes data rate to as low as 1K fps.
Other height triangulation systems implement very expensive custom-dedicated acquisition and processing designs but suffer from lack of flexibility of imaging and algorithm to meet future application needs.
Therefore, there is an imperative need of to provide flexible, cost effective and efficient height triangulation systems and methods.